DE1237352B - Tape recorder - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY Int. Cl .:

Gllb

DE UTSCHES

PATENT OFFICE

EDITORIAL

German class;

Number:
File number:
Registration date:
Display day:

42g-18

1237 352
K48791IXa / 42 |
January 26, 1963
March 23, 1967

The invention relates to a tape recorder in which for recording and playback a tape of a To wind the supply reel on a take-up reel and in which the motor is pivoted so that one of its two shaft extensions is in one operating position with the winding and in the other cooperates with the supply reel support.

In a known device of this type, the motor is pivoted by means of a hand lever. To secure the respective operating position, the hand lever is in its working positions by a Pen held. Such an arrangement takes up a relatively large amount of space and is also prone to failure.

These disadvantages are eliminated according to the invention in that the motor operated with direct current with a change in its direction of rotation from an operating position caused by reversing the polarity of the drive voltage to be brought into the other.

It is known to use direct current motors by reversing the polarity of their drive voltage in their direction of rotation to change. In the invention, however, the motor is due to the influence of its torque components brought into the desired operating position when changing its direction of rotation. This does not apply the previously necessary swiveling of the motor by hand. The mechanical switching device is saved, and the weight of the device and its manufacturing costs and susceptibility to failure are reduced. Since the device is switched over by reversing the polarity of the direct current source it is possible to connect a remote control to the device. Also the pressing of the tape to the magnetic head during advance and the lifting of the tape from the magnetic head during Reverse can occur at the same time when reversing the polarity of the drive voltage from the swivel movement of the motor can be controlled from.

Some exemplary embodiments are shown schematically in the drawings. It shows F i g. 1 an embodiment in plan view,

F i g. 2 the same embodiment in side view, partially broken away,

F i g. 3 schematically shows an essential part of the same embodiment and

F i g. 4 shows a side view of another embodiment, in which, to the first shown, a tape pressing device is added;

Fig. 5 shows the embodiment according to Fig. 4 in plan view,

F i g. 6 diagrammatically shows the essential part of the same embodiment,

Tape recorder

Applicant:

Satoshi Kawauchi, Tokyo
Representative:

Dipl.-Phys. Η. Schroeter

and Dipl.-Ing. K. Lehmann, patent attorneys,

Munich 25, Lipowskystr. 10

Named as inventor:
Satoshi Kawauchi, Tokyo

F i g. 7 is a plan view of FIG. 6 and

8 shows a circuit diagram of an exemplary embodiment of the device for reversing the polarity of the current source for the electric motor and remote control; Fig. 9 shows another embodiment with a coil drive,

Fig. 10 shows a further embodiment with a coil drive and

11 shows a further embodiment with a roller drive according to the invention.

On the basis of FIG. 1, 2 and 3 the principle of the reel drive of a tape recorder according to the invention shown.

M is a small, variable-speed DC motor, which is provided with shaft extensions 1 and 2 at both ends. The electric motor M is arranged in the middle of a support ring 3 , in which it is freely pivotable with pins 4 or the like, which engage in the support ring 3 on the one hand and the central part of the housing of the electric motor on the other. The support ring 3 for the electric motor M is in turn freely pivotable with the aid of pins 8, 9 or the like in supports 6, 7 which are fastened to a base plate 5. The pivoting of the support ring 3 is limited, however. In the base plate 5 , a take-up reel support 10 and a supply reel support 11 are rotatably mounted, between which the electric motor M is arranged. These coil carriers 10 and 11 are arranged so that when the polarity of the electric motor M is reversed, its shaft extension 1 on a rubber ring 10 a of the take-up reel carrier 10 or the shaft extension 2 of the electric motor M on a rubber ring due to the reaction

709 520/341

11 a of the reel support 11 can attack. When the shaft extension 1 on the rubber ring 10 ″ of the take-up spool carrier 10 in FIG. 1 engages, the shaft extension 2 can be attached to the rubber ringlla on the underside of the disc of the take-up spool carrier 11 in FIG. 1 to be attacked. The support ring 3 can be pivoted in such an area that these states of contact can be maintained. The switching process triggered by reversing the polarity of the power source, which causes the shaft extension 1 to engage the take-up reel support or the shaft extension 2 to engage the supply reel support, is described below with reference to the in FIG. 8 described circuit diagrams.

One end of a spring 12, for example a leaf spring, is fastened to the housing of the electric motor M, at the free end of which a support 13 is provided, which is constantly pressed against the circumference of the take-up reel carrier 10. The spring force of the spring 12 is set so that when a take-up reel 15 is placed on the reel carrier for the purpose of winding a tape 17 and switching on the motor , the shaft extensions 1 and 2 are set at the beginning of the winding of the tape 17 on a straight line, which the shaft 10 b of the winding reel carrier 10 and the pivot axis of the electric motor M determined by the pin 4 connects. If the load on the electric motor M also increases as the diameter of the tape roll 17 on the take-up reel 15 increases, the shaft extensions 1 and 2 gradually pivot in the direction of FIG. 3 away from the straight line connecting the shaft 10 b of the take-up reel carrier 10 and the pivot axis of the electric motor M determined by the pin 4 , so that the braking effect of the support 13 pressed by the spring 12 against the circumference of the take-up reel carrier 10 gradually increases. As a result, the speed of the electric motor M decreases and the change in the speed of the tape 17 to be wound on the take-up reel 15 is reduced.

The support ring 3 is provided with a stop 14 which determines the pivot angle of the shaft extensions of the electric motor between the positions that they occupy with the smallest and largest diameter of the tape roll on the take-up reel or at the beginning and end of the winding process , so that the Electric motor is not pivoted more than necessary.

The speed of the electric motor M is variable, and its direction of rotation can be reversed by reversing the polarity of its direct current source. If the direct current source is now polarized so that the electric motor M runs in the normal direction of rotation, the shaft extension engages the rubber ring 10 "of the take-up reel carrier 10 , so that it is rotated around its shaft 10 b , which rotates the take-up reel 15 on the thereby the tape 17 is wound up. When the polarity of the direct current source is reversed, the electric motor M rotates in the opposite direction. As a result of the reaction, the shaft extension 2 engages the rubber ring 11 α of the supply reel carrier 11 , so that it is rotated about its shaft 11 &, which then rotates the supply reel 16 so that the tape is rewound.

The electrical process causing this switchover is illustrated in FIG. 8 described. It

it goes without saying that in the normal direction of rotation a recording or playback takes place while when the motor is running in the opposite direction, the tape is rewound.

If in the in FIG. 1, 2 and 3, the electric motor M runs in the normal direction of rotation so that recording or playback can take place, the speed at which the tape 17 passes the magnetic heads 18, 19 is independent of the diameter of the take-up reel 15 wound tape 17 reduced and the tape 17 withdrawn at constant speed. A pressure roller is not provided.

F i g. 4, 5, 6 and 7 show another embodiment in which to the one in FIG. 1, 2 and 3 shown A tape pressure device is added to the reel drive. But there are only those essential parts shown. This embodiment is arranged so that the pressing of the with constant speed of the withdrawn tape against the magnetic head during recording and Playback and the moving away of the tape when reversing with the polarity reversal of the direct current source caused pivoting of the DC motor is coupled.

In the in F i g. The embodiment shown in FIGS. 4 to 7, in addition to those in FIG. 1 to 3, a connecting rod 20 is also provided, freely rotatably connected to the housing of the electric motor M. At the other end of the connecting rod, one end of a lever 21 is articulated, which is pivotably mounted on the base plate and at the other end of which a band pressing member 22 in the form of a three-pronged fork is provided. The fork 22 is arranged between a playback head 18 and an erase head 19 . These two heads are attached to the base plate. The connecting rod 20 can also be replaced by a cord.

In this embodiment, when the electric motor M is started in the normal direction to rotate the take-up reel base 10 for recording or playback so that the motor M moves in the direction of the direction shown in FIG. 5 is pivoted solid arrow, it pushes the connecting rod 20 in the direction of the solid arrow, so that the lever 21 is pivoted and thereby moves the band pressure fork 22 towards the magnetic heads 18 and 19 and that between the prong 22 a and the prongs 226 and the tape 17 guided by the tape pressing fork 22 is pressed against the magnetic heads 18 and 19 so that it fits snugly against them and recording or reproduction can be carried out. When the electric motor M starts running in the opposite direction to rotate the supply reel support 11 in the rewind direction, the motor is rotated in the direction of the direction shown in FIG. 5 swiveled by the dashed arrow and pulls the connecting rod 20 in the same direction, whereby the lever 21 is swiveled and the tape pressure fork 22 is pulled away from the magnetic heads 18 and 19. As a result, the tape 17 guided between the prongs 22 α and the prongs 22 b and 22 c of the tape pressing fork 22 is pulled off the magnetic heads 18 and 19 , whereby the frictional resistance is eliminated, which can be attributed to the pressing of the tape against the magnetic heads 18 and 19 was. This is the return

wrap easier. The electrical switching process for reversing the polarity of the direct current source for the electric motor M (see Fig. 8) therefore not only causes a switchover between recording or playback on the one hand and rewinding on the other hand, but also the pressing of the tape against the magnetic heads 18, 19 or moving the tape away from the magnetic heads 18, 19 by means of the tape pressing fork. This makes it possible to create a tape recorder without a mechanical switching device and without spring-loaded tape pressure elements.

The polarity reversal of the current source for the direct current motor is used by the method shown in FIG. 8 switching device shown, the mode of operation now with reference to the F i g. 8 will be described.

In Fig. 8 , M is a DC motor of the type mentioned above. 23 and 25 are rotary switches coupled to one another. The rotary switch 23 has a rewind contact 23 a, a recording and playback contact 23 b, a stop contact 23 c, a remote control contact 23 e and a plate receiving contact 23 d. The rotary switch 25 has a switching arm 26. Connections to the contacts of this switch are only provided if they are required (for remote control). With 28 a current source for a transistor 27, with 29 a current source for the electric motor M is designated. A relay 30 has contacts 31, 32, 33, 34, 35 and 36. The contacts 32 and 35 are normally applied to the contacts 31 and 34, respectively, but are switched over when the relay 30 is energized. A remote control device 37 is provided with a push button switch 38 for recording and playback and another push button switch 39 for rewinding.

When, in this embodiment, the switching arm 24 of the rotary switch 23 rests against the contact 23 b , a current flows through the transistor 27, so that the electric motor M is in a circuit which is supplied by the current source 29 via the transistor 27, the contacts 31 and 32, the electric motor M and the contacts 35 and 34 goes to ground. As a result, the electric motor M runs in the normal direction. If you now bring the switching arm 24 of the rotary switch 23 to the contact 23 "to the plant, the relay 30 is energized and actuates its contacts 32 and 35. This closes a circuit that is from the power source 29 via the contacts 36 and 35, the EIektromotorM and contacts 32 and 33 goes to ground. The polarity of the power source of the electric motor M is therefore reversed, so that it rotates in opposite directions. If you bring the switching arm 24 of the rotary switch 23 to the contact 23 e to the plant, an electrical connection is established with the remote control device 37, so that when the push button 38 is pressed, an electric current flows through the transistor 27 and the switching arm 26 of the rotary switch 25. As a result, the electric motor M runs in the normal direction as if the switching arm 24 of the rotary switch was in contact with the contact 23 b . When the push button 39 is pressed, however, the relay 30 is energized, so that the electric motor M rotates in the opposite direction than if the switching arm 24 of the rotary switch 23 was in contact with the contact 23 a .

It has been described above that recording or reproduction is performed when the electric motor M rotates in the normal direction of rotation while

when the electric motor M runs in the opposite direction, rewinding takes place. Therefore, through the purely electrical process, which is triggered by operating the rotary switch, optionally a recording or playback on the one hand or initiate a rewinding process. When the rotary switch is on Are switched remotely, this electrical switching can also be done by remote control.

ίο In the in F i g. 1 to 8 can therefore be initiated by a purely electrical switch, through which the DC source of the electric motor is reversed, either a recording or playback on the one hand or a rewinding process on the other hand, the tape is pressed against the heads or pulled away from them at the same time and the polarity reversal can also be done by remote control. If the remote control device is equipped with a sound transducer

ao, which can work as both a microphone and a loudspeaker, it is possible to use one of the tape recorder remote location to make a recording and this at the location of the recording to control by playing back, because at any time the rewinding of the tape carrying the recording and playback of the recording can be effected.

F i g. 9 shows another embodiment of the invention with a reel drive. Here's a 40-year-old Designated take-up reel carrier, which has a one-piece rubber ring on its outer circumference 40 a is provided. There is also a one-piece rubber ring on the outer circumference of a supply reel support 41 41a provided. The coil carriers 40 and 41 are parallel to each other and in a certain Distance from one another rotatably mounted in the base plate 5 of the tape recorder. Between these bobbins 40 and 41, an intermediate disk 42 is arranged, which is attached to the rubber ring 40 a or 41 a can attack at right angles. This intermediate disk is freely displaceable on an intermediate shaft 43, which is carried by the base plate S so that the washer is optionally attached to the rubber ring 40 a or 41a can attack. Against the outer circumference of the washer 42 is a Inclined shaft extension l 'of a variable-speed DC motor M pressed on, as was also used in the previously described exemplary embodiments. In this case it is the electric motor M, however, fixedly attached to the bracket 3 ', so that, in contrast to the previous Embodiments described is not freely movable.

If in such an arrangement the DC power source is polarized so that the electric motor in revolves around the normal direction of rotation, the shaft extension 1 'rotates in the direction of the pulled out drawn arrow. Since the washer 42 is pressed diagonally against the shaft extension 1 ', it receives a torque and is driven by a component thereof along the intermediate shaft 43 pressed in Fig. 9 to the right against the rubber ring 40a of the take-up reel carrier 40, so that this and the take-up reel 15 is rotated and the tape 17 is withdrawn for recording or playback will.

If the direct current source for the electric motor M by means of the in F i g. 8 switching input

direction is reversed, the shaft extension 1 'rotates in the direction of the dashed arrow, so that the intermediate disk 42 by a component of the torque along the intermediate shaft 43 in F i g. 9 is pressed to the left against the rubber ring 41a of the supply reel carrier 41 to rotate this and with it the supply reel 16 so that the tape 17 is rewound.

In the in F i g. The embodiment of the invention shown in FIG. 10, the take-up reel carrier 40 and the supply reel carrier 41 are as in the embodiment according to FIG. 9 rotated with the aid of the washer 42, which as in FIG. 9 is arranged between the take-up reel support 40 and the supply reel support 41 and can act at right angles on the rubber ring 40 λ or 41α. According to FIG. 10, however, the intermediate disk is fixedly arranged on the intermediate shaft 43, which is carried by the base plate 5 with the aid of a bracket 44 in such a way that the shaft 43 is freely rotatable and can be displaced to the left and right to a limited extent. The shaft 43 is provided on one side with a coupling 45, with the coupling part 47 of which a disk 46 can be brought into engagement by means of a spline. The shaft extension 1 'of the electric motor M is pressed against the outer circumference of the disk 46, as in the embodiment according to FIG. 9 pressed at an angle. When the disk 46 is rotated in one direction, it rotates the shaft 43 via the coupling part 47, while when the disk 46 is rotated in the opposite direction, the disk 46 engages the coupling part 47 after a certain rotation and thereby rotates the shaft 43 .

The drive of the take-up reel support 40 and the supply reel support 41 by means of the electric motor M differs with regard to the mode of action of the screw arrangement described above from the mode of action of the embodiment according to FIG. 9, but this corresponds to this in other functions. When the electric motor rotates in its normal direction of rotation, the torque of the shaft extension 1 'is transmitted to the take-up reel carrier 40 as a result of the effect of a torque component, while after reversing the polarity of the power source for the electric motor M by means of the in FIG. 8 , the electric motor M rotates in the opposite direction and the torque is transmitted to the supply reel carrier under the action of a torque component.

The embodiments shown in FIGS. 9 and 10 represent modifications of the first embodiment in which the tape is drawn off by means of a reel drive. According to this process, the tape is drawn off at a constant speed. If a constant braking force is applied in the middle of the tape take-off, which is stronger than the tension of the tape in the opposite direction, the speed of the electric motor decreases as the diameter of the tape roll on the take-up reel increases, so that the change in the speed of the tape is reduced. This method can also be applied to a springless tape pull-off device according to FIG. 1 and 3 are applied.

Fig. 11 shows another embodiment of the invention in which it is applied to a roller drive will. A small constant speed one

DC motor M 'has a shaft extension 1 or 2 at both ends and is as described above pivotally mounted with pin 4 in a support ring 3. A drive roller support 48 is in the Near its circumference provided with a rubber ring 48 a. The take-up reel 15 is similar to that in FIG Embodiments described above formed. It is rotated with a pulley 49, which sits on a support shaft 50 for the take-up reel in such a way that the disc 49 spin can when a strong counter-torque acts on the shaft 50. By means of a belt 55 is the Pulley 49 is coupled to another pulley 54 which is connected to the drive roller carrier 48 is rotatably connected. A pressure roller 51 is pressed against the circumference of the drive roller 56, so that the belt 17 is taken along by the rotating drive roller. The pressure roller is from carried a lever 52 which is freely rotatably mounted at one end in the base plate and from a tension spring 53 is pressed against the drive roller 56. With 57, 58 tape guides are designated. The other reference numerals denote the same parts as in the previous embodiments.

If, in this embodiment, the electric motor M 'is driven by the in FIG. 8 switching device shown is caused to rotate in the normal sense, the shaft extension 1 runs in the direction of the solid arrow and is pressed against the rubber ring 48 a of the drive roller carrier 48, so that the drive roller 56 is rotated. Since the pressure roller 51 is pressed against the outer circumference of the drive roller 56, the tape 17 inserted between the pressure roller 51 and the drive roller 56 is moved at constant speed from the supply reel 16 to the take-up reel 15 and can be recorded by means of the speaking and listening head 18 or playback can be used, the erase head 19 of course only being effective during recording. The tape 17 withdrawn at a constant speed by the drive roller 56 is then taken up on the take-up reel 15, which is rotated by the pulleys 54 and 59 and the belt 55. When the DC power source for the electric motor M 'is supplied by the means shown in FIG. 8 switching device shown is reversed, so that the electric motor M runs in opposite directions, the shaft extension rotates in the direction of the dashed arrow and thus also rotates the drive roller carrier in the opposite direction. However, since the resistance to pivoting of the electric motor around the pin 4 in the support ring 3 is weaker than the resistance to the rotation of the shaft of the drive roller 56, the electric motor M 'is pivoted in the direction of the solid arrow, so that when the Shaft extension 1 from the drive roller carrier 48, the shaft extension 2 engages the rubber ring IIa of the supply reel support and the supply reel 16 is rotated in the rewinding direction. Means are of course provided which move the pressure roller 51 away from the drive roller 56 when the tape 17 is rewound.

In the embodiment according to FIG. 11, the one shown in FIG. 4 to 7 shown device for pressing of the tape on the magnetic head and to move the tape away from the magnetic head.

Claims (4)

be seen. Furthermore, since the electric motor with the in F i g. 8 switching device shown can be controlled, remote control of the device is possible. With regard to the possible fluttering and whining with a tape recorder, an advantage is achieved in that by reducing the diameter of the shaft of the electric motor, its speed increases and thus the amplitude of the vibrations transmitted to the reel or drive roller carrier is reduced, so that the fluctuations in the rotation are negligible become small and a complete pulling off of the tape is possible even with an electric motor with low torque. Furthermore, the advantage is achieved that the tape can be pulled off at a constant speed even with a variable-speed electric motor. Patent claims: 1. Tape recorder in which a tape from a supply reel is used for recording and playback to wind on a take-up reel and in which the motor is pivotally mounted so that each one of its two shaft extensions in one operating position with the winding and in the other interacts with the supply reel carrier, characterized in that the motor (M) operated with direct current also runs through Reversing the polarity of the drive voltage causes its direction of rotation to change from an operating position to be brought into the other. 2. Tape recorder according to claim 1, characterized in that the electric motor (M) is freely pivotable and a spring (12) is attached to it, the free end of which constantly presses against the circumference of the take-up reel carrier (10) , so that the speed of the motor (M) is regulated according to the diameter of the tape lap of the take-up reel (15). 3. Tape recorder according to one of the preceding claims, characterized in that a lever (21) is pivotably attached to the electric motor (M) which presses the tape (17) against the magnetic head (18, 19) during recording and playback and during rewinding of the tape (17) on the supply reel (11 ) pulls this from the magnetic head (18,19). 4. Tape recorder according to one of the preceding claims, characterized in that a switching device for reversing the polarity of the power source for the direct current motor (M) has a connector for connection to a remote control device (37) , by actuating a switch between a recording or playback process on the one hand and on the other hand, a rewinding operation takes place. Considered publications:
German Patent No. 954 743;
German Auslegeschrift No. 1108 452;
"Radio und Fernsehen", 1962, H.22, pp.692 iis 694. For this purpose 2 sheets of drawings 709 520/341 3.67 © Bundesdruckerei Berlin